Safety control for gaseous fuel burners



y 1952 G. B. SOLOVIEFF 2,596,796

SAFETY CONTROL FOR GASEOUS FUEL BURNERS Filed Jan. 14, 1947 2 Sl-IEETS-Sl-iEE'I l INVENTOR Hm ATToRNEY y 1952 G. B. SOLOVIEFF 2,596,796 I SAFETY CONTROL F OR GASEOUS FUEL BURNERS Filed Jan. 14, 1947 2 SHEETS-SI-IEET 2 .Nv fieopgefi 505006917.

ATTORNEY Patented May 13, T9522 SAFETY CONTROL F R GASEOUS FUEL RNERS George B. Solovieff, South Gate, Calif., assignor to Robertshaw-Fult'on Controls Company, a

corporation of Delaware Application January 14, 1947, Serial No. 722,004

Claims.

This invention relates to safety control apparatus for fuel burners and, more particularly, to combined resetting and indicating devices for thermoelectric safety controls.

It has been proposed to reset a thermoelectric safety device and open the safety valve by utilizing the simple rotation of a dial instead of a push-button operation. In this invention, the same expedient is employed but in a more compact and economical arrangement due to coaxial relation of the various parts. The object of facilitating the resetting operation is thus preserved in the improved arrangement.

An object of the invention is to reset the thermomagnetic safety device and indicate the control position by a common operation.

Another object of the invention is to indicate clearly the operational sequence for resetting the control.

Another object of the invention is to automatically retain the resetting dial in an operated position if the control is properly set in operation.

Another object of the invention is to automatically return the setting dial to unoperated position if the control is not functioning.

Another object of the invention is to prevent flow of fuel to the main burner during the resetting operation while permitting such flow to a pilot burner.

Other objects and advantages will become apparent from the following description taken in connection with the accompanying drawings,

wherein: I

Fig. l is a cross section of a thermoelectric safety control embodying the invention;

Fig. 2 is a diagrammatic end view on a reduced 2 periphery spaced from the Wall of the opening 22. The valve stem 26 extends through the valve member 24 and is provided with a nut 28 for securing the valve member 24 in position on the valve stem '26. The nut 28 supports one end of a coil spring 30 which has itsopposite end supported upon a stuffing-box member 32 positioned at one end of magnet housing 34 exteriorly thereof. The opposite end of the magnet housing 34 is supported within an end cap member 3'6 threadedly secured to the casing l0. Suflicient clearance is provided between the outer side wall of the magnet housing 34 and the inner sid wall of the end cap member 36 to accommodate a cupshaped actuating sleeve 38 which is slidable over the magnet housing 34 and projects therefrom into engagement with the nut 28 to which it is scale showing the resetting means and indicating Fig. 6 is a schematic view of a fuel burning apparatus having the invention applied thereto.

Referring more particularly to the drawings, the control device shown therein comprises a casing H] having an inlet opening l2 communicating with an inlet chamber l4 and an outlet I opening [6 communicating with an outlet cham-' ber I8. A partition 20 separates the inlet chamber 14 from. the outlet chamber t8 and is provided f;

with a passage 22 extending therethrough axially of the casing l0.

' A valv member 24 is supported within the pa s sage 22 upon a valve stem 26 andhas outer;

secured.

The end wall of the magnet housing 34 adjacent the stufii'ng box member 32 is suitably apertured for the reception of a connecting stem 40 having one end fastened to the valve stem 26 by a pin 42 while the opposite end is secured to an armature member 44 positioned within the magnet housing 34. Th armature member 44 is adapted for cooperation with a horseshoe magnet 46 which is rigidly supported in the housing 34 on a hollow terminal connection 48 extending axially of the end cap member 36 and threadedly engaging the end wall thereof for projection on the exterior thereof. The arrangement is such that when the valve member 24 is in the position shown in Fig. 1 of th drawings, the armature member 44 is spaced from the pole faces of the horseshoe magnet 43 and upon movement of the valve member 24 to the left as viewed in the drawings, the armature member 44 will become engaged with the pole faces of the horseshoe magnet 46. The usual winding 50 is provided for the horseshoe magnet 46 and is electrically connected through th terminal connection 48 with a suitable source of electrical energy which will be described more fully hereinafter.

The actuating sleeve 38 is adapted to be reciprocated into and out of engagement with a ball valve 52 and cause movement thereof away from its seat 54. The ball valve seat 54 is formed on a connection 56 secured to the end cap mem ber 36 and being provided with a coil spring 58 for biasing the ball valve 52 toward its seat 54.

- The connection 58 is provided with an outlet opening Bllfor connection to a pipe or conduit, to be described hereinafter.

The valve stem 26 extends through the valve "SSMfimber 24011 the sideoppositetlie nut 2-8 and has a hollow end '62 within which a conical head 64 of a reset stem extension 66 is received. The hollow end 62 is provided with an annular recess 63 to accommodate a spring ring II! which serves to retain the conical end 64 in position. The reset stem extension 66 is secured to a reset stem I2 and an annular diaphragm element I4 is clamped between the stem I2 and the extension 66 at its median portion. As will be more fully described hereinafter, the reset stem I2 has a projecting end, shown more clearly in Fig. 5,

which is provided with oppositely disposed flats; I6 adjoining a cylindrical reduced portion or neck I8 which, in turn, adjoins a rectangular end portion '80.

The valve member 24 is shown as seated upon a second diaphragm element 82 of annular form and having its outer area supported by a retaining ring 84 on one side thereof. The inner area of the second diaphragm 82 is supported on one side and inner periphery thereof upon a lantern member 86 which is slidably mounted upon the reset stem extension 66 and upon which the retaining ring 84 is slidably mounted. A plurality 'of apertures 88 are provided in spaced arrangement in the wall of the lantern 86 to permit flow of fuel from the inlet chamber I4 to the outlet chamber l8 past the valve member 24 when the latter is disengaged from its seat on the second diaphragm 82. The second diaphragm 82 engages with a seat 96 formed on the partition 26 and such engagement is maintained under bias of a coil spring 92 which is operative atone end against the retaining ring 64 and at the opposite end against a second retaining ring 94. tern 86 has a reduced shoulder 93 on which the retaining ring 94 is mounted.

The first-mentioned diaphragm I4 abuts the retaining ring 94 and is biased by the coil spring 62 against a shoulder 85 formed on an end flange 96 which is threaded to the casing I6. The diaphragm I4 thus provides a closure for the end of the casing ID containing part of the resetting mechanism. The end flange 66 is recessed to receive an outer housing 98 which engages at its outer end With a support plate I66 for the diaphragm I4. The outer housing 98 has an inner annular flange 99 which slidably receives the reset stem I2 and also an outer annular flange IGI which slidably receives an inner housing I92 carried on the reset stem I2. A coil spring I04 is operative for biasing the two housings 98 and I92 apart. In addition, a flat spring I65 is positioned on the reset stem 12 between the housings 98 and I62 to act in conjunction with the spring I64 for override purposes as will be apparent hereinafter.

Secured to the outer end face of the end flange 36 and by a plate I56 and screws I68 is a cupshaped housing H6 having apair of oppositely disposed slots II2 extending from the open end thereof and terminating midway from the closed end. The slots I I2 are adapted for the reception of oppositely disposed lugs II4 formed on the periphery of a ball retaining plate II6 which is thus secured in the housing I I6 against rotation. The ball retaining plate has an axial aperture In of rectangular form to receive the flats I6 on the reset stem I2 and prevent rotation of the latter. A cover member II8 extends over the slotted end of the housing III) and is secured thereto by the screws I26, for retaining the ball retainin plate I I 6 in position.

"Positioned one on each side of the ball retaining plate H6 within the housing III] and the cover The lanthe magnet winding 50.

member II8, respectively, is a pair of disc elements I22 and I24. The disc element I22 is supported upon a shoulder I25 formed on the inner housing I02 and is thereby biased toward the ball retaining plate H6 by the coil spring I04 operative on the housing I62. The disc element I24 is secured by welding, brazingor other means to a hollow shank I26 which extends from the cover I I8 and carries a dial I28 secured against rotation thereon. The dial is provided with a pointer I30 cooperable with indicia off, on, and Light pilot which may be marked, as at I32, in spaced relation on the cover I I8 as indicated in Figs. 2, 3 and 4 inclusive.

Thedisc element I22 is provided with a pair of diametrically opposite apertures I34 which are adapted to register with a pair of arcuate slots I36 formed at diametrically opposite points in the disc element I24. The ball retaining plate H6 is also provided with a pair of diametrically opposite apertures I38 adapted to register with the apertures I34 and the slots I36. The apertures I38, however, are of larger diameter than the apertures I34 or the width of the slots I36 and accommodate a pair of ball elements I40 which are freely slida'ble therein but which are unable to pass through the apertures I34 in the disc element I22. A-torsion spring I42 is operative between the shank I26 and the cover I I8 to .cause return movement of the dial I28 andassociated parts when manual pressure is released on the dial I26.

As shown more clearly in Figs. 2-4 inclusive, the disc element I24 is provided with an annular flange I44 on the opposite face thereof to the retaining plate H6: and which extends over the reset stem portions I6 and I8 when the parts are positioned as shown in Fig. 1. The flange I44. is inturned at its outer end and provided with an axial opening I46 which has a pair of oppositely disposed arcuate walls I48 and a pair of V-shaped, indented, connecting walls I56. The reference characters A, B, C and D denote the four sides of the connecting walls I56 in counterclockwise order in Figs. 2-4.

The rectangular end portion 86 of the reset stem I2 has opposite arcuate walls I52 (Fig.5) or substantially the same diameter as the reset stem 72. There are two opposite flat sides I54 which lie in substantially the same plane as the flats I6 on the reset stem I2. The reduced cylindrical portion I8 intermediate the rectangular end and the flats I6 is diametrically uniform with the thickness of the rectangular end portion 80 across the fiat sides I54. Thus, the arcuate walls I52 are slidably engageable with the arcuate walls I48 of the opening I46. The connecting walls I50 of the opening I46 are adapted to extend substantially parallel with the fiat sides I54 of the rectangular end 86 in certain positions of the parts.

In Fig. 6 of the drawings a schematic view of the improved control device is shown connected to contrelamain burner I 56 having a pilot burner I58 in lighting proximity thereto. The terminal connection 48 serves to connect the leads I66 and I62 of a thermocouple I64 in circuit with The thermocouple I64 is exposed to the heat of a flame at the pilot burner I58 and forms a means responsive to the heat of the burning fuel for energizingthe electromagnet comprising windingtdmaghet-fi and armature 44. The main burner :56 is'shown as. con e d. by arip jzt i t9 h o t 5 of t control body I 8 while the inlet I2'is connected to a pipe I68 leading from a source of fuel supply. The pilot burner I58 has a conduit I connected to the pilot connection 60 on the control body I 0.

In the operation of-the device, it may be assumed that the burners I56 and I58 are not operating so that the parts of the control device are in the positions shown in Figs. 1 and 2. To place the burners in operation, the dial I28 is manually rotated in a clockwise direction, as shown by the arrow in Fig. 2, from the position shown in Fig. 2 in which the ball elements I40 engage a pair of the end walls of the arcuate slots I36. After approximately 45 revolution, the disc element I24 will have rotated to the position shown in Fig. 3 and this rotation is relatively to the ball retaining plate 6 and the other disc element I22. Such relative rotation is limited by the opposite pair of end walls of the arcuate slots I36 coming into abutting relation with the ball elements I40. In this position, the sides B and D of the axial opening I46 extend parallel with the fiat sides I54 of the rectangular end portion 80 of the reset stem 12. The reduced cylindrical portion 18 of the reset stem I2 is opposite the axial opening I46 so that free rotation of the disc element I 24 is permitted.

Further rotating movement of the dial I28 in a clockwise direction will cause the ball elements I40 to be forced down and under the surface of the disc element I24, such movement of the ball elements I40 being axially of the retaining plate II 6 due to their capability of passing through the apertures I38 therein. The position of the ball elements I40 after this further rotary movement relative to the disc element I24 and the retaining plate H6 is shown in Fig. 4 it being noted that the legend Light pilot is now in registry with the pointer I30. Moreover, the sides A and C of the axial opening I 46 now extend parallel with the flatsides I54 of the rectangular end portion 80. I

It will be apparent that the ball elements I40 are prevented from rotating with the disc element I24 during the further rotary movement thereof described. These ball elements I40 are retained in fixed relation to the other disc element I22 by the relatively stationary ball retaining plate H6. Consequently, the retaining plate II6 forms a means for causing movement of the ball elements I 40 into interposed relation between the disc elements I22, I24 by converting the torque applied by the disc element I24 on the ball elements I 40 into an axial thrust on the other disc element I22. This thrust is sufficient to cause an axial movement of the valve member 24 and the armature means 44 to the left as viewed in Fig. 1 in a manner now to be described.

The axial movement of the disc element I22 is transmitted to the various elements of the control as follows, it being noted that the movement in all cases is axial where this term is omitted; to the inner housing I02 and to the outer housing 98 through the coil spring I04 and flat spring I05 interposed between these housings and which are not compressed at this time. The movement of the outer housing 06 is transmitted thereby to the plate I00, the diaphragm member I4 and the retaining ring 94. The bias of the coil spring 62 is overcome by the movement of retaining ring 04 and the lantern element 06 moves relative to the other retaining ring 84 and causes the action of the springs I04, I05, and 92.

inner area of the seconddiaphragm 82 'to flex parts now occurs as follows:

6 with increased force due to compression of the spring 92 toward the other retaining ring 84.

The second diaphragm 82 moves the valve member 24 and its stem 26 which is connected to the reset stem extension 66 and reset stem 12. The projecting portion of the reset stem I2 having the flats I6 is pulled through the rectangular aperture I I! in the ball retaining plate I I6 by the reset stem movement and the rectangular end is now housed within the axial opening I46. It will be apparent that the parallel arrangement of the sides A and C with the flat sides I54 permit this movement and that the arrangement isv retained without rotation of the parts being possible due to the rectangular aperture II'I being complemental to the flattened end 16 of the reset stem I2.

The movement of the valve member 24 is transmitted to the armature 44 by the connecting member 40. The armature is thus placed in engagement with the pole faces of the magnet 46 and the bias of the coil spring 30 is overcome. The ball valve member 52 is moved oil its seat 54 by the action of the actuating sleeve 38 which is moved by the nut 28 attached to the valve stem 26.

The purpose of the springs I94 and I05 is apparent when it is mentioned that the armature 44 is seated against the pole faces of the mag-net 46 before the ball elements I40 have completely withdrawn from the arcuate slots I 36 in the disc element I24. Thus, the two springs I04, I05 provide an override arrangement to ensure seating of the armature 44. The springs I04, I05 are, consequently, slightly compressed at the time the position shown in Fig. 4 is reached.

Flow of fuel through inlet opening I2, connection 56, pilot outlet 60, and conduit I10 to the pilot burner I58 now occurs. The flow of fuel to the main burner I56 is still cut-oil due to the engagement of the valve member 24 with the second diaphragm 82. The pointer I30 is indicating the Light pilot position on the indicia I32 shown in Fig. 4. After the pilot burner I56 is lighted and the thermocouple I64 becomes heated thereby, the magnet 46 will be energized by its winding 50 to retain the armature 44 in its attracted position where. it is operative for retaining the valve member 24 in open position as soon as this is permitted as now to be described.

The manual torque on the dial I28 is now released and the torsion spring I42 serves to rotate the disc element I24 and the dial I28 in a counter-clockwise direction as viewed in Fig. 4. The position shown in Fig. 3 is then reached due to the sides B and D of the axial opening I46 coming in contact with the flat sides I54 of the rectangular end portion 80. Further rotary movement of the dial I28 will thus be prevented and the on position of the indicia I32 will be alinged with the pointer I30.

The ball elements I40 are at this time in registry with the original pair of end walls of the arcuate slots I36 and will be biased into their initial position within the slots I36 due to the Consequently, a reversal of the position of certain the override of springs I04, I05 is relieved and the inner housing I02 moves to return the disc element I22 to its initial position shown in Fig. l. The outer housing 98 and plate I 00 are retracted under .bias

of the spring 92 which causes diaphragm 14- to be seated on the shoulder 95 by the retaining ring 04. The lantern 86 is thus caused to return to its original position and the flexing of the second diaphragm 82 ceases. As previously mentioned, the engagement of the outer area of this second diaphragm 82 with the seat 90 is preserved at all times. The disc elements I22 and I24 are biased toward each other and engage opposite sides of the ball retaining plate I IS, the ball elements Hi) being no longer interposed therebetween.

The valve member 26 is retained in its open position relative to the second diaphragm 82 as it is held by the connection with the armature do against the bias of spring 39. Fuel can flow from inlet l2, past valve member 24 into lantern 86 and through apertures 88 therein to the outlet 16. The fuel is conducted by the pipe I66 to the main burner [56 and ignited by the pilot burner flame. During this open setting of the valve member 24 the fuel is prevented from leaking into the resetting portion of the control by the engagement of the diaphragm M with the shoulder 95.

In the event that the pilot burner flame becomes extinguished, then the thermocouple I6 1 no longer energizes the electromagnet and the armature 44 moves to unattracted position under bias of the spring 38. The valve member 24 is thus moved to closed position in engagement with the second diaphragm 82 so that flow of fuel to the main burner is prevented. In addition, the ball valve 52 is no longer held away from its seat 54 by the actuating sleeve 38 and flow of fuel to the pilot burner will cease. The reset stem 12 moves to the right and causes the cylindrical section 18 of the projecting portion thereof to be housed within the aperture I46. Hence, the spring [42- is free to rotate the dial I28 to register the off position of the indicia I32, and cause the disc element I24 to return to its initial position shown in Fig. 2. The parts of the control device are then in the positions shown in Fig. 1 ready for another resetting operation.

Many changes may be made in the arrangement of parts and details of construction without departing from the invention as defined in theappended claims.

I' claim:

1. In a control apparatus, control means adapted for axial movement between operative positions and being biased to one of said positions, an axially movable stem operatively associated with said control means, a control member coaxial with said stem and rotatable relative thereto, means for causing axial movement of the control means to another of said positions upon rotary movement of the control member to a limiting position, said means including a pair of elements one having operative torque transmitting engagement with the control member and the other having operative engagement with said stem, interengaging means for .said

elements adapted to transmit movement therebetween, and means cooperable with said interengaging means and operative upon rotation of said control member for converting the torque applied thereby to said one element into an axial thrust on said other element sufficient to cause said axial movement of the control means to the other said position, and means operable between said stem and said one element for limiting return movement of said control member mom said limitingposition, while said control ,means is in said other position. Y

- e rn 3 control; apparatus, control means adapted for axial movement between operative positions and being biased to one of said positions, an axially movable stem operatively associated with said control means, a control member coaxial with said stem and rotatable relative thereto, means for causing axial movement of the control means to another of said positions upon rotary movement of the control member to a limiting position, said means including a pair of elements one having operative torque transmitting engagement with the control member and the other having operative engagement with said stem for axial movement therewith, interengaging means movable relatively to said elements and being adapted to transmit movement therebetween, and means cooperable with said interengaging means and operative upon rotation of said control member for converting the torque applied thereby to said one element into an axial thrust on said other element, said interengaging means and said other element being thereby moved relatively to said one element sufficiently to overcome said bias and cause said axial movement of the control means to said other position and detent means operable between said stem and said one element for limiting return movement of said control member from said limiting position when said control means is in said other position, said detent means beingineffective when said control means is in said one position.

3. In a control apparatus, control means adapted for axial movement between operative positions and being biased to one of said positions, a control member mounted forv rotary movement relative to the control means, and means for causing axial movement of the control means to another of said positions upon rotary movement of the control member, said means including a pair of apertured disc elements one having operative engagement with the control member and the other having operative engagement with the control means for axial movement therewith, a plurality of ball elements having an inoperative position each extending partly with in one of the apertures in one disc element and partly within a registering aperture in the other disc element, said ball elements being incapable of extending completely through the apertures in either disc element, and means interposed between said disc elements and apertured to receive said ball elements therethrough, said last means being secured against rotation relative to said other disc element and being constructed and arranged to prevent translatory movement of said ball elements relative to said other disc element whereby rotation of said one disc element relative thereto. will effect movement of said ball elements out of the apertures in said one disc element into interposed relation between said disc elements and establishing an operative position thereof for applying an axial thrust on said other disc element sufficient to overcome said bias and cause said axial movement of the control means to the other said position.

4. In a control apparatus, control means adapted for axial movement between operative positions and being biased to one of said positions, a control member mounted for rotary movement relative to said control means and having a plurality of operative positions, and means for causing axial movement of thecontrol means to another of. said positions upon rotary movement of the control member. to a limitingi'posi-tion, saidmeans including apa-irof elements one having operative torque transmitting engagement with the control member, connecting means between the other said element and the control means having a portion extending into operative engagement with said one element, interengaging means for said elements adapted to transmit movement therebetweenand to said connecting means, means cooperable with said interengaging means and operative upon rotation of said control member for converting the torque applied thereby to said one element into an axial thrust on said other element sufficient to cause said axial movement of the control means to said other position, and means operable between said portion of the connecting means and said one element for limiting return'movement of said control member from said limiting position while said control means is in said other position. v 5. In a control device, control means adapted for axial movement between operative positions and being biased to one of said positions, means for retaining said control means in another of said positions after said control means has been moved thereto, means for actuating said control means to said other position including a control member mounted coaxially of said control means for rotary movement relative to said control means in one direction, spring means for returning said control member in a reverse direction when said rotary movement is terminated, means adapted for rotary movement with said control member having abutments thereon, and means cooperable with said control means for engagement with said abutments when said control means is retained in said other position for limiting the reverse movement of the control member and being free from said abutments when said control means is in said one position.

6. In a control device, control means adapted for axial movement between operative positions and being biased to one of said positions, means for retaining said control means in another of said positions after said control means has been moved thereto, a control member mounted for rotary movement relative to said control means in one direction, means for causing axial movement of said control means to said other position upon rotary movement of said control member in said one diretcion, said last means including a pair of elements one having operative engagement with the control member and having abutments thereon, spring means for returning 7 said control member in a reverse direction when said rotary movement is terminated, and connecting means between the other said element andthe control means having a portion extending into engagement with said abutments when said control means is retained in said other position for limiting reverse movement of the control member.

7. In a fluid control device, valve means adapted for axial movement between open and closed positions for controlling the flow of fluid, an electromagnetic device having an armature operative for retaining said valve means in an open position, means for biasing said valve means to closed position and said armature to inoperative position, means for resetting said armature in operative position including reciprocable means operatively associated with said armature and valve means, a control member mounted for rotary movement relative to said armature and valve means and subjected to a torsional bias, means for causing axial movement of said armature to said operative position and said valve means to open position, said last means including a pair of elements one having operative engagement with the control member for rotational movement therewith and the other having operative engagement with the valve means for axial movement therewith, a wedging device cooperable with said elements and movable into interposed relation therebetween upon rotation of said control member against said torsional bias to impart axial movement to said other element and overcome said valve biasing means, means for energizing said electromagnetic means sufiiciently to hold said armature in operative position, and means cooperable with said valve means for operative engagement with said control member when said valve means is in said open position to limit movement of the control member under said torsional bias and being free of said control member when said valve means is in said closed position.

8. In a fluid control device, valve means adapted for axial movement between open and closed positions for controlling the flow of fluid, an electromagnetic device having an armature operative for retaining said valve means in an open position, means for biasing said valve means to closed position and said armature to inoperative position, means for resetting said armature in operative position including reciprocable means operatively associated with said armature and valve means, a control member mounted for rotary movement relative to said armature and valve means, means for causing axial movement of said armature to said operative position and said valve means to open position, said last means including a pair of apertured disc elements one having operative engagement with the control member and the other having operative engagement with the valve means for axial movement therewith, a plurality of ball elements each extending partly within one of the apertures in one disc element and partly within a registering aperture in the other disc element, said ball elements being incapable of extending completely through the apertures in either disc element, means interposed between the disc members and apertured to receive said ball members therethrough, said last means being secured against rotation relative to said other disc ele ment and adapted to prevent translatory movement of said ball elements relative to said other disc element whereby rotation of said one disc element in one direction relative thereto will effect movement of said ball elements into interposed relation between said disc elements to overcome said biasing means, means for energizing said electromagnetic means sufiiciently to hold the armature in operative position, and yieldable means for torsionally biasing said control member and causing rotation of said control member and said one disc element in another direction to effect movement of said ball elements out of interposed relation to permit movement of said armature to inoperative position when said electromagnetic means is not energized.

9. In a fluid control device, a casing having a fluid supply passage and inlet and outlet openings communicating therewith, a control valve member between said openings and biased to one controlling position, an armature operatively associated with said valve member, electromagnetic means cooperable with said armature for retaining said valve member in another controlling position, resetting means for moving said armature and said electromagnetic means relative to each other to establish anoperative connection therebetween and set said valve member in said other position, and an annular diaphragm extending across said passagebetween said openings and being operatively engageable by said reset means and by said valve member in said one controlling position to interrupt communication between said openings, said diaphragm being yieldable during the resetting operation for maintaining said operative engagement and interruption of communication between said openings.

10. The device as claimed in claim 9 wherein said reset means and valve member operatively engage said diaphragm on opposite. sides thereof adjacent theinner periphery thereof, and means for clamping a portion of said diaphragm .ad-

jacent the outer periphery thereof in sealing-engagement with said casing.

GEORGE E. SOLOVIEFF.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

